sub-process patching when file depends on #! for python executable

[karthiknadig]

The command line that it generates for subprocesses has ./manage.py as the first entry in the list that it passes to subprocess.Popen() - try inserting sys.executable there.

Originally posted by @int19h in #265 (comment)

[karthiknadig]

/cc @fabioz

[judej]

Moving this issue to discussion as an enhancement request for comments and upvotes.